The present invention relates to farm implements and, more particularly, to a seed metering cassette for a seeding implement, such as an air seeder.
Air seeders are commonly towed by tractors to apply seed, fertilizer, or micro-nutrients or any granular product to a field. For purposes of this application “seeding” shall include the application or deposition of any granular or particulate material onto a field, and “seed” shall include seed, fertilizer, micronutrients, or any other granular material that may be applied onto a planting surface, farm field, seedbed, and the like. It is generally advantageous to tow an air seeder in combination with a tilling implement, one behind the other, to place the seed and fertilizer under the surface of the soil. An air seeder has as its central component a wheeled seed cart which comprises one or more frame-mounted seed tanks for holding product, generally seed or fertilizer or both. Air seeders also generally include a volumetric metering system operable to measure a fixed volume of seed per unit of linear distance and a pneumatic distribution system for delivering the product from the tank to the soil.
The volumetric metering system is configured for distribution of product from the tank to the distribution headers of the seed tubes. The metering system typically includes a meter roller assembly employing augers or fluted cylinders (meter rollers) situated in a meter box assembly secured below the tank.
Typically the meter box will have a series of outlets known as runs that each leads to the distribution lines of the pneumatic distribution system. The pneumatic distribution system generally includes an air stream operable to carry product metered by the meter roller assembly through the distribution lines to a series of secondary distribution manifolds (“headers”), which in turn distribute product to a group of ground openers mounted on the seeding implement operable to place seed in the ground. The ground openers are configured to evenly deliver the product to the span of ground (the “seedbed”) acted upon by the seeding implement.
To reduce manufacturing costs and eliminate consumer confusion is customizing an air seeder, most manufacturers offer a seed metering assembly in which the meter box and the fluted meter roller that are sized to meter granular material to a preset number of secondary headers. One of the drawbacks of such a construction is that not all implements require or have the preset number of secondary headers. For those implements having fewer secondary headers, sections of the seed metering assembly must be capped off. The result is that the consumer is required to purchase a seed metering assembly that may be larger than the consumer requires.
Additionally, for some implements, there can be some inconsistency in the number of outlets of the secondary headers. This inconsistency is generally the result of the implement having a particular frame configuration that may be required to achieve a particular transport configuration. Since the meter roller meters granular material to each of the secondary headers at the same metering rate, the amount of granular material per outlet will be higher for those secondary headers having a fewer number of outlets. As a result, the seedbed serviced by the ground opener units that are fed by the headers having fewer outlets will be over-seeded compared to the seedbed serviced by the other ground opener units. This discrepancy in the application of granular material, which heretofore has been generally ignored, can ultimately lead to inconsistent seeding and thus inconsistent per row crop yields.